OK, I've now tested the memory expansion and it works perfectly.
It is a Zydec FPU1208 ZIP V2 - with "FPU1208 - A1200 Accelerator - (C) J Williams 1993,94" written on the back.
It takes ZIP Ram and is populated with 4MB, but can have another 4MB added later to upgrade it to 8MB if needed as it has the spare sockets for it.
The card has an on/off switch that can easily be reached with the card installed in the A1200 trapdoor, so you can disable the ram if needed.
It also has sockets to add a FPU and supports both PGA and PLCC 68881/2 FPUs, but none are currently installed.
I've taken some images below showing the board, both front and back, as well as a closeup of the battery to show it is in good condition and hasn't ever leaked. I've also run the card on an A1200 and have taken 2 screenshots showing the board displayed in the early startup menu, and also in Workbench showing it providing 4MB of fast ram.
It is also definitely PCMCIA friendly as I used to use this with various PCMCIA expansions such as a SCSI Squirrel adapter and a PCMCIA HDD.
If you would like this board then it will be £25 + £3.50 1st class recorded postage, so total would be £28.50. I will PM you my details.
I should have the original box it came in when new somewhere and will try to locate it for you if I can. Otherwise it will be well packed for posting.